1. Field of the Invention
This invention relates to a magnetic tape cartridge, and more particularly to a magnetic tape cartridge comprising a cartridge casing and a single reel around which a magnetic tape is wound and which is contained in the cartridge casing for rotation.
2. Description of the Related Art
There has been known a single reel magnetic tape cartridge comprising a flat cartridge casing which is formed by upper and lower shell halves and is substantially square in shape and a single reel around which a magnetic tape is wound and which is contained in the cartridge casing for rotation. Such a single reel magnetic tape cartridge has been used for retaining data of a computer or the like. A tape outlet opening is formed in a side wall of the cartridge casing and when the magnetic tape cartridge is used, i.e., when the magnetic tape cartridge is loaded in a recording and reproducing system as, for instance, an external storage for a computer and information is to be recorded on the magnetic tape or information recorded on the magnetic tape is to be read, the magnetic tape wound around the reel is drawn out through the tape outlet opening.
In such a magnetic tape cartridge of one type, a leader block is fixed to the leading end of a leader tape which is connected to the magnetic tape and when the magnetic tape cartridge is not used, the magnetic tape is fully wound, around the reel with the leader block fitted in the tape outlet opening to close the tape outlet opening. In the case of the magnetic tape cartridge of this type, when the magnetic tape cartridge is loaded in the recording and reproducing system, a drive means in the recording and reproducing system engages with engagement teeth on the reel exposed outside at the central portion of the lower casing half and a tape drawing mechanism in the recording and reproducing system chucks the leader block and draws the magnetic tape outside the cartridge casing into a tape running path of the recording and reproducing system.
In another type, the tape outlet opening is closed and opened by a lid which is rotatable between a closing position where it closes the tape outlet opening and an opening position where it opens the tape outlet opening, the lid being urged by a spring toward the closing position. A hook member is fixed to the leading end of a leader tape which is connected to the magnetic tape and when the magnetic tape cartridge is not used, the magnetic tape is fully wound around the reel with the hook member retracted inside the tape outlet opening and the lid held in the closing position. In the case of the magnetic tape cartridge of this type, when the magnetic tape cartridge is loaded in the recording and reproducing system, a drive means in the recording and reproducing system engages with engagement teeth on the reel exposed outside at the central portion of the lower casing half and a tape drawing mechanism in the recording and reproducing system moves the lid to the opening position, chucks the hook member and draws the magnetic tape outside the cartridge casing into a tape running path of the recording and reproducing system.
Recently, the recording and reproducing system (will be referred to as xe2x80x9ctape drive systemxe2x80x9d hereinbelow) comes to require employment of a leader pin about 3 mm thick in place of the leader block or the hook member. However attempts at meeting such requirement have encountered a difficulty that it is difficult for the tape drawing mechanism in the tape drive system to surely chuck such a thin leader pin.
In view of the foregoing observations and description, the primary object of the present invention is to provide a magnetic tape cartridge which is provided with a leader pin which can be surely chucked by the tape drawing mechanism in the tape drive system.
In the following description, a term xe2x80x9ca magnetic tapexe2x80x9d sometimes means xe2x80x9ca magnetic tape with a leader tape connected theretoxe2x80x9d.
The magnetic tape cartridge in accordance with the present invention comprises a cartridge casing, a single reel around which a magnetic tape is wound and which is contained in the cartridge casing for rotation, and a leader pin fixed to the leading end portion of the magnetic tape and is characterized in that the leader pin is provided at its opposite ends with engagement portions which are brought into engagement with a tape drawing mechanism of a recording and reproducing system when the magnetic tape cartridge is loaded in the recording and reproducing system, and the end face of each engagement portion is provided with a recess at which the tape drawing mechanism chucks the leader pin.
With this arrangement, though simple in structure, the tape drawing mechanism of the recording and reproducing system can surely chuck the leader pin.
It is preferred that each engagement portion be provided with a smaller diameter portion and a flange on the outer side of the smaller diameter portion and the recess be formed on the outer end face of the flange at the center thereof.
For example, the leader pin may comprise a body portion provided with the aforesaid engagement portions at its opposite ends and a clamp member which is press-fitted on the body portion sideways with the leading end portion of the magnetic tape sandwiched therebetween.
With this arrangement, the leader pin can be easily fixed to the leading end portion of the magnetic tape.